Cryptography refers to the securing of communications across various mediums.

That might mean transmitting messages via public channels, like radio signals that will be

meaningful to the intended recipient but to no one else. And it might mean figuring out how

to send emails that can't be intercepted, or telegraph missives that are less likely to be read by someone who has managed to tap the cable across which that missive was sent.

Modern cryptography often involves the securing of digital messages transmitted via internet-based channels,

including things like emails and e-commerce transaction information, and more

fundamentally, handshake-style information that helps manage connections between devices, protocols

that allow you to connect to websites from your smartphone, for instance.

In earlier, pre-digital computer times, cryptography almost always meant encryption,

the scrambling of characters in a handwritten letter, for instance, which would allow the recipient

who would have some kind of unscrambling knowledge or access to the proper code that would allow

them to make sense of seemingly nonsensical words or letters or numbers,

or through the use of what's called a one-time pad, which is essentially a use-once-then-discard

formula that allows the possessor of this pad, of de-encryption information, the ability to unscramble a code that has been

encrypted by someone with the same pad, and thus the same set of one-use codes arranged in

the same order, a method of encryption that would be all but impossible to decrypt, lacking

the exact pad possessed by the encryptor.

Today, cryptography also refers to non-incryption-related methods of securing these communication channels.

Algorithms can be used to lock down information in such a way that only folks with the right algorithms and the proper processing power

can see what's being said, a method somewhat similar to those one-use pads that spies, from the

Middle Ages to the Cold War, used whenever possible. But there are other schemes, heavily reliant on

advanced mathematical theory and sophisticated computer science

...